Re: Datagram TLS

[Scott Fluhrer <sfluhrer@cisco.com>]

On Fri, 30 Jan 2004, Eric Rescorla wrote:

> This seems relevant to these working groups.
>
> Although TLS is quite useful as a generic security layer protocol for
> lots of applications, it is limited by its reliance on datagram
> transport. It seems like it would be useful to deploy TLS-style security
> for datagram apps. To this end, Nagendra Modadugu and I have designed a
> variant on TLS which works properly over datagram transport but is
> otherwise intended to be as similar to TLS as possible.
>
> http://www.ietf.org/internet-drafts/draft-rescorla-dtls-00.txt
>
> Comments welcome...

One obvious question is how you handle the switchover if one of the sides
decides to rekey.  In this case, a packet encrypted with the old key
might be slow, and arrive at the destination after the rekey
negotiation has completed.  TLS handles this because it can assume strict
message ordering.  IPSec handles this with the SPI value.  How does DTLS
prevent a packet being decrypted with the wrong key?

-- 
scott